Pump



June 12, 192s.

c. R. MEsToN ET AL 1,673,262

PUMP

Filed July 1o, 192s s sheets-sheet 1 312mm ma l lime 12. 192s.

C. R. MEsToN E'r AL PUMP Filed July 10, 1926 3 Sheets-Sheet 2 June 12, 1928. 1,673,262

c. R. MEsToN ET AL PUMP Filed July 10, 192s s sheets-#sheet s ATToRNE 5 Patented Juie '12,' 1928.

:PATi-:N

T oFFicE.

CHARLES R. MESTON A ND' 'ALECK W. MESTON, OF `YONIKERS, NEW YORK, ASSIGNORS TO THE STAOOLD CORPORATION, OF NEW YORK, N. Y., A CORPORATION OF NEW YzORK.

PUMP.

This invention relates to umps arid particularly to gear pumps of t e type used for `'was given to power consumed oi' efliciency.

Various improvements have Later, such pumps. while retaining the valveless feature, were designed to handle gases,4 such as retrigerants. and sealing mediums, such as Water, oil or glycerine.u

were used as packing to obtain pressure or vacuum.,

been-made to givey this type of pump increased eiciency and to render it capable of handling'fhigh gas pressure, but these -improvements on ac count 'of the valvele'ss feature of the pumps f wereonly theoretically eiiicient at one asf sumerl differential of pressure ,between the intake and the outlet While 1n many cases, sucli .isret'rigerating machines, this differential is not constant and varies bot-h at the c Y inlet and at the outlet. Forinstance, the

gears and teeth have vtheir temperature raised by the operation 'ofthe pump and friction and when the gas remains in contact with the hot teeth. it expands, thus creating pressure in the teeth before the mechanical compression takes. place by the int-efimeshingv Y of the teeth. This isjparticularly true if any Wet gas or liquid comes in contact with' the hot teeth; This pressure created in theteeth `requires more power vfor compression and thus cuts downthe efiiciency of the pump. `AAAlso. the discharge port is located and dimensio-ned to fulfill certain lpredetermined theoretical conditions. the intake` gas or'air at zero gauge or one atmosphere pressure and an outlet pressure of four atmospheres or forty-live pounds pressure. The inlet Willtll a tooth at one .atmosphere and the pressure will reach four.

atmospheres at a point Where the intermeshing of the ,teeth has reduced the area-threequai'ters and the lresultant capacity 1s onequarter. In the valveless pump if'the outletcontrol is uncovered exactly at this point,

it will give efficient compression provided the port is the right size. v the outlet portl is .too large andthus For instance, assume- Application Ie-d July 10, 1926. Serial No. 121,516.

opens too soon, .that is before' four atmospheres pressure has been developed, then the air or gas from the tank at four atmospheres will rush back into thepump and into the tooth having thepartially compressed gas therein and this high pressure air or gas must be expelled, thus requiring unnecessary and additional power and cutting down the eiiiciency of the On the other hand, if the outlet port is u too small, and the port is not uncovered until a higher pressure than four atmospheres has been reached inthe tooth, this excess pressure will consume unnecessary power.

-In other Words, if the .valveless pump is correctly designed for'zero gauge inlet and forty-five pounds outlet,v.or any otherp predetermined differential in pressures', -it will -be etlicient under that exact differential 'and any variations in linlet or outlet will` render the pump inefficient. y

In the type of pump above described, oil orsome' other sealing liquid is introduced into the pump to seal the tooth. This oil is yfed 'runder pressurev developed f by' the pumpv pum t pressures "(5" l vsalientobject to provide a pump of the type specified so constructed and arranged that it will operate efficiently under` varying conditions of inlet and outlet pressures..l

videa' pump having its inlet port' or ports solocated that pressure created lin the teeth due to expansion or vola-tilizat-ion ofthe lgals -Will be reduced to a-.minimum.

Another object oftheinvention is to pre AAnother object of the invention is to provide a pump having inlet ports so locatedA Athat the incoming gas 0r air or--other Huid lWill be in contact with the gear teetha mini,-v

mum period of time. i A I Another object of the invention vide a pump having outlet that back pressure from t e pressure tank Willnot 'reach the gear teeth and operate'to cut down -theeiiciency' of the pump.

is to proorts so arranged ido . Another object of the invention isto pro# I, vide 'a pump having outlet ports soconfA structed and arranged that the pump will operate efficiently( t rough a wide 4range ofv videl in a pump of the `type specified, means .for lnsuring a uniform and constantsupply of sealngliquidfor the gear 'teeth regardless of variations in pressure in the pump and in the liquid.

'Further obyects of the inyention'iwill'appear from the following specication takenl in connection with the drawings, which form va part of this application, and in which Fig. 1 is a sectional elevation of .a pu'mp constructed in accordanc'ewith the invenjtion showing the inlet port and ythe conduits for` conducting sealing liquid'to thetgear` `disposed in intermeshing .relation with reteeth;

Fig. 2 is a sectional elevation taken at right angles to Fig. 1, -this view being taken substantially on line 2-2 of Fig. 3;

Fig. 3 is an enlarged elevational view taken substantially on line 3-3 of Fig. 2;

Fig.' 4 is an' enlarged sectional elevation' showing the check 'valve in the outlet port ofthe pump;`

Fig. 5 is a sectional elevation of'ainother embodiment of the invention showing particularly the. position of lthe intake or inlet.

ports, this view being Itaken snbstan'tia'lly on -line 5 5 of Fig. 6;

Fig. 6 is a sectional right angles to Fig. 5;

Fig. 7 is adiagrammatic view illustrating the positions of the inlet and outlet ports of the pumps shown irl-Figs. 5 and 6; and

Fig. Sis an enlarged sectional elevation of the metering valve for the sealing liquid.`

The invention brieliy described consists of elevation taken at` a um havin intermeshinv"v ears t erein P P e and in'the preferred embodimentA of t e invention, the inlet ports as shown inn-Figs. 5, 6 and 7 are located on the same side of a i plane passing through theaxes of the intermeshing` gears as the discharge or outlet port or ports. .The inlet ports are .preferably located in a position to conduct the gas orliuid to the teeth justprior to their moving into mesh so4 that the gas, such as a refrigerant, .will remainl in contact withv the teeth a ininimum amount of time, Furthermore, lthe inlet ports should cut oi the Vintake bef0refthefinjection of sealing liquid.

' Th'i's'prevents the gas from being expanded vby long vcontact with the hot teeth. In order te prevent back pressure fromjthepressure tank from being communicated to the gears l and teeth, the outlet port or portsy lof the pump are provided with vcheck valves so constructed that they will open nutwardly avv-ayV from the teeth but will be closed by the tank pressureif the pressure developed in the In additionnto the features enumerated, the

pump is not equal to the pressurein the tank;

pump is provided Witha meterin device so constructed that' a constant andv 'uniform supply ,of sealing liquid will be Aintroduced into the pump under varyingconditionsiof pressure. This is accomplished by so oon'- s'tructing the metering device that as the. 'pressure increases, the inlet opening from the sealing liquid conduitto the pump will In the embodiment of the invention illustrated inFigs.. 1 to 4 i'nclusive, the pumpv comprises a casing 10-ha'ving a pair of gears4 11 and 12 rotatablyA mounted therein and spect to each other. These gears are carried bya casing block orih'ead 13 which'is insertled in the casingl() and has a flange 14 secured thereto. vThe opposite end of the cas-r ing 'is'closed 'by a head' v15and,av strainer 16 of gauze. or other suitable material is carried bythev casing head-15 and is positioned betweeny the casing andthe out-let conduit 17 forthe gas or other iiuid pumped.

In the pump illustrated the gears 11 and 12 have herring-bone teeth. The casing block 13 has a pair of chambers 20 and 21 `formed therein, the gas or other'lltlid to be pumped being introduced'into the chamber 21 through a conduit22 and the sealing liquid or oil being introduced into the chamber 2O through conduit 23. J

The chambers and 21 preferably have filters 25 and 26 therein to filter, the inlet gas and the sealing liquid.

The pump gears are mounted in o enings and 31 formed in va block 32 and t e ends of the gears are closed by plates 33 land 34. f

The plate33 abutsat its` outer face against shown in Fig. 1. AA' conduit 40 leads from th e chamber 21 to thel intake port or passage 41 formedin the block 32. The sealing liquid is conductedv vfrom the 'chamber 20 throughjconduits 45 vand 46 to branch con-y duits 47 and `48 and is led through the con duits-47 and. 48 to the t/eeth of the'gars. l

In. theform ofV the "invention shown in These ports are arranged as showinl in Fig. 3 in the form of a V, thelower port' 50 being located approximately at the point of deepest mesh'of the gear teeth. The ports 51 and 52 are located oppositelthe periphery of the gear 11 and the ports 53 and 54 are located opposite the periphery of the gear 12.

'IMI

a surface 35 oft-he casing head or block 13 `Figs. 1 to 4 'a plurality of outlet ports `isprovided.

Each of the 'outlet ports consists of a valve chamber 55v having a. valve seat ,56' at one end and a valve such asa ball valve 57 adapted tov seat on the valve seat.. A spring 58 acts to press the valveagainst the seat and is enclosed by a. ring or collar 59 disposed `at the outer end of the valve chamber.

The outlet ports as "shown-in Fig. 2Lare. 4mounted in the plates33 and 34 at opposite sides ofthe gears and the plates are longitudinally grooved as shown at 6.() the groovesforming conduits for the'outlet gas. From the groove or conduit60, the gasand, of course, portions of the sealing liquid pass into a chamber 61 which surrounds the pump Aproperand is formed' in the casing l0. The gas passes outwardly from the chamber through the gauze or strainer 1 6 and the oil or sealing liquid drops down into the bottom of the casing and .is returned therefrom to.

the chamber 2O through the conduit 23. In the embodimentof the invention shown in Figs. 5 to 8` inclusive, the pump elements are mounted in the same nfanner .as in4 the preceding figuresA but the pump inlet port-s are located in 'different positions` from the inlet ports in the, vfirst embodiment -of' the invention and a metering device is provided in the oil'intake conduit. I

Referring to, Figs. 5 to 8 inclusive, it will be seen that the intake 'gas passes from the n gas is conducted to the gear teethjust prior to their moving into-mesh and, therefore, is in contact with the teeth a minimum period of time. This, .of-course, will prevent as far as possible the 'expansion of the gas due to Y' its Contact with the hot teeth.

The meteringdevce shown indetail in Fig. 8 introduced into the oil orsealing liquid system intern'iediate. the conduit 80 which' receives the oil'fronrthe pump casing and the conduit' or conduits 8l which conductthe oil tothe gear teeth.

n The metering device consists of a tubular member having a threaded portion 82 which is threaded into the-pump casing and a longitudinally extending portion 83 which forms the lvalve'chamber.v 'The @valve champlug 85 having a plurality of openings 86 therethrough and having'atapered,`longi= tudinal portion 87 royided with a longi? tudinalopening 88 t eren. Theportion87 er has positioned at one eml'thereofV a ring 84 and has positioned at itsopposite end a` extendsupwardly into. the.' valve'chamber and is surrounded by a springv 89, one end of which seats against the plug 85 and the other end of which engages a sleeve `or c ollar-90. lt will' be noted that the sleeve or lcollar 90'overlaps the ringl 84 or, stated differently, has a smaller opening therethrough..

than the'ring 84.

Furthermore, the collar 90 has a smaller outside diameter than the inside diameter of the valvev chamber formed vby portion 83'. The metering device voper/lates as follows.

lVhen the pump is operating at low pressure'l vand the pressure of the-sealing liquid is,

therefore, low, .it will pass through the metering device by` passing through the ring 84 around and through 'the collar 90-and plug 85. If, however, the pressure of sealwillcaus the collar or sleeve 90 to'be forcedw downwardly, thus decreasing the area of the passage through the opening -n the collar` and decreasing the .amount-of liquid passing through the openings 86. In this way 'varia-'- u through the vcentral passage 88 in the plug 85 andalso through the openings 86 .in the ing liquid is increased. its increased pressure i.

imv

- tions in pressureare compensated. for by the l i metering device and av uniform and 'constant supply ofsealing liquid is fed tothe gears,

' From the foregoing specification itwill he seen'tha't the pump is so construizted and arranged'that itwilloperate efficiently/.under Wide variations in the differential, between the intake and outlet pressures and "by reason of the check valves, the efficiency-of the pump isv increasedsincebaek pressure from the pressure tank cannot reach the gea-i1 teeth. Furthermore, inthe embodiment of the invention shownin Figs. 5 to 7 1inclusive,

the intake ports are so located that the pressure created inthe teeth` due `to the'contact duced to a minimum.

lIn the diagrammatic showing in Fig. 7, the gas in tfake is shown atA, sealing liquid intake at B, and discharge ports at C.-V Gas'- inlet ports A should cutoli before the gear .teeth pass into mesh and sealing liquid in'- `take portsvB also should belocated to introduce the sealing liquid to the, teeth before -the teeth mesh.

g Although certain'vspeeitic embodiments of the invention have been,p'n'ticularly shownVZ and described, it willbe understood vvthat the' invention liscapable of lmodification-and that changesin the construction and in the `arrangement-"of the various --cooperating lof the intake gas with the hot gears is reparts may be made without departing from' the spirit .vorscopev of the invention, as vexpressed in the following claims.

Vhat we claim is: r Y1. A pump comprising a casing,- a pair of' intermeshing gears therein, pump intake ports and pump outlet ports, all ofsaid ports beingdisposed pon the same vside/of a plane passing through the axes of said gears.

2. A pump comprising a casing, a pair of intermeshing gears therein, intake ports located adjacent the approaching-portions of the gears, and discharge ports for said pump located adjacent` the intermeshingv portions of the gears.

3. A-pump comprising a casing',in ter meshingl gears therein, vintake portsj communicating with said'gears and located above .the a- Xes of rotation of said gears and adja` cent the approaching portions thereof, and

`discharge or outlet ports communicating m'unicat-ing with'the intermeshing i with the intermeshing portions of 'said gears.

4. A pump comprising a casing, interlmeshiiig gears therein, intake ports communicating with said gears and located opposite and incommun'ication vwith noninteil meshing portions of the. gears 'at the ends of -theteeth'and abovetlieaxes of rotation of the gears 'and discharge Aor outlet ports comportions of said gears.

5. A pump'comprising a casing, ay pair of intermeshing gears therein,- a conduit for conducting sealing'iquidio the teeth of `lsaid,gears and pressure controlled means in said conduit for insuring the 'passage of a uniform quantity of vliquid to the gears regardless of\ the pressure forcing the liquid ,through the conduit. p p

-6. .A pump comprising a casing. a pair of' intermeshing gears therein, a conduit foi` conducting sealing liquid to the .teeth hf said gears-and a pressure responsive metering device in said Aconduit for maintaining a uniform flow of liquid to t-lie gears under v varying conditionsof pressure. f

7. A pump comprisingfa 'casing, a pair of intermeshing gears thereinaconduit for conducting sealing liquid' to the teethof said gears and ai metering-device in'said conduit,

said device comprising a casing having an.- Y inlet. port and an outlet port 'and means 1ntermediate said ports adaptedv tov control the fiiowA of liquid through said ports.

8i AI pump comprising a "casing, a pair of intermeshing gears thereiiLf a conduit for 'conducting sealing liquidto the teethof said gears and a metering device in said conduit, said device comprising a casing'liaving an inlet port`\ and fan. outlet port and spring` V vpressed means intermediate said ports'adapt# ed to control the flow of liquid through said ports.

-9. A pump comprising a-casing,"a\pair of ,y

intermeshing gears therein, outlet ports communicatingy with the v intermeshing por- Itions of said gears at'diiferent stages in the intermeshing thereof and' valves in said 'ports adapted to openl away from thevgears. l

meshing thereof, and outwardly openingv4 'i valves in said ports.

12. A pump comprising a. casing, intermeshing gears therein,.a plurality of outlet ports disposed at the ends of said gears and in alinement withl intermeshing portions -of said gears at different stages in the interineshing thereof and-checklvalves .in said ports.

,of intermeshing gears therein, intakel ports communicating with the ends of theteeth-ssfof said gears as the teeth of the gears are A pump comprising a casing,a` pair approaching, said intake ports being located to cut olfthe intake prior to t-he meshingof 'A the teeth. l 14. A pump comprising a casing, a pair oflintermeshing gearstherein, intake ports communicating with the teeth of said-gearsI as theteeth of the vgears are approaching, said intake'ports being located to cut ofi'- the intake prior to the/meshingv ofithe4 teeth, and

'means for introducing sealing liquid to the egear teeth after the intake gas is lintroduced and before/the teeth. move into mesh.

intermes in gears therein,l intake ports communicating withthe teeth of said gears jasthe teeth. of'tlieqears are approaching,v

15. A ump comprising a casing, a pairof v said intake'ports being located to cut off tha` Y 'intake prior to the `meshing' of the teeth,

and a discharge port communicating with the vintermeshing teeth.

.In witnesswheieof, my hand this 6th day of July, 1926. CHARLES RQMESTON.. In Witness i my handM this titlidlgy of J uly, 1926.

EoK W. Mss'roN. f

I have hereunto set l whereof, I have-*hereuntol set i 

